General Electric Company

Rensselaer Polytechnic Institute

Cardiomag Imaging, Inc.

Alexander Seth Ross

Jeffrey Michael Ashe

Gary Jude Saulnier

Veera Venkata Lakshmi Rajesh Langoju

Norman Arnold Turnquist

Wei Tan

Hua Xia

Naresh Kesavan Rao

Kevin Thomas McCarthy

Danian Zheng

David So Keung Chan

Juntao Wu

Krishnakumar Sundaresan

Boleslaw Szymanski

Yun Li

Ran Niu

Karsten Sternickel

Mark Embrechts

Zhilin Wu

Richard Gawrelski

Matthew Damian Pietrzykowski

Weihua Gao

Long Han

Ning Liu

A system and method for soft-field reconstruction are provided. One method includes establishing an initial estimate of a property distribution of an object, using a first reconstruction process to reconstruct an estimate of the actual property distribution and using a second reconstruction process different than the first reconstruction process to further reconstruct the estimate of the actual property distribution. A solution from the first reconstruction process is used as an initial estimate in the second reconstruction process.

System and method for soft-field reconstruction

A soft-field tomography system includes a plurality of transducers configured for positioning at a surface of an object. An excitation driver is configured to generate a precomputed default excitation pattern for the plurality of transducers. A processor stores the precomputed default excitation pattern and a corresponding predicted response for the precomputed excitation pattern. The processor further stores one or more precomputed fault excitation patterns and corresponding predicted response for the fault excitation patterns corresponding to one or more fault conditions of the plurality of transducers. A response measurement device is configured to measure a response at one or more of the transducers to determine if a fault condition exists. If a fault condition exists, the processor at least one of instructs the excitation driver to generate a precomputed fault excitation pattern or uses a predicted response that corresponds to the fault condition for a soft field tomography process.

System and method for correcting fault conditions in soft-field tomography

A system and method for transducer placement in soft-field tomography are provided. One system includes a plurality of transducers configured for positioning at a surface of an object in a non-soft-field tomography configuration. The system also includes an interface and a processor communicating with the plurality of transducers via the interface. The processor is configured to perform soft-field sensing using soft-field data acquired by the plurality of transducers.

System and method for transducer placement in soft-field tomography

An iteration method for computing a distribution of one or more properties within an object comprises defining a first mesh of the object, applying an excitation to the object, computing a response of the object to the applied excitation, obtaining a reference response of the object corresponding to the applied excitation, computing a distribution of one or more properties of the object, and updating at least a subset of the nodes of the first mesh to form an updated mesh of the object. The distribution of one or more properties of the object is computed using the computed response, the reference response, and the first mesh. The first mesh includes a plurality of nodes and elements. A connectivity relationship of the subset of the nodes in the updated mesh remains the same as in the first mesh.

Soft field tomography system and method

A system and method for determining physiological parameters based on electrical impedance measurements is provided. One method includes obtaining electrical measurement signals acquired from a plurality of transducers coupled to a surface of an object and constructing a system matrix to define one or more relationships between the impedance measurement signals. The method also includes decomposing the system matrix to separate the electrical measurement signals.

System and method for determining physiological parameters based on electrical impedance measurements

A system and method for artifact suppression in soft-field tomography are provided. One method includes obtaining an excitation pattern and applying the excitation pattern to an object, wherein the excitation pattern includes a plurality of frequency components. The method also includes measuring a response at one or more of a plurality of transducers coupled to the object and separating the responses among the plurality of frequency components to suppress one or more artifacts.

System and method for artifact suppression in soft-field tomography

A novel Levenberg-Marquardt like second-order algorithm for tuning the Parzen window &#x3c3; in a Radial Basis Function (Gaussian) kernel. Each attribute has its own sigma parameter. The values of the optimized &#x3c3; are then used as a gauge for variable selection. Kernel Partial Least Squares (K-PLS) model is applied to several benchmark data sets to estimate effectiveness of second-order sigma tuning procedure for an RBF kernel. The variable subset selection method based on these sigma values is then compared with different feature selection procedures such as random forests and sensitivity analysis. The sigma-tuned RBF kernel model outperforms K-PLS and SVM models with a single sigma value. K-PLS models also compare favorably with Least Squares Support Vector Machines (LS-SVM), epsilon-insensitive Support Vector Regression and traditional PLS. Sigma tuning and variable selection is applied to industrial magnetocardiograph data for detection of ischemic heart disease from measurement of magnetic field around the heart.

Sigma tuning of gaussian kernels: detection of ischemia from magnetocardiograms

A system and method for soft-field tomography data acquisition are provided. One system includes a plurality of transducers that correspond to a plurality of channels, and an excitation driver coupled to generate excitation signals for the plurality of transducers. The system also includes a single reference excitation source from which excitations are generated and one or more derived excitation sources. The one or more derived excitation sources derive excitations from the single reference excitation source that are applied to each of the plurality of channels. The system further includes a response detector and a reduced bit digitizer in each of the plurality of channels configured to digitize a measured response difference between the measured response at one or more of the transducers and at least one of an excitation of the single reference excitation source or an excitation derived from the single reference excitation source or a separate reference.

System and method for soft-field tomography data acquisition

A fiberoptic multi-parameter sensing system for monitoring turbomachinery system shaft static and dynamic torques, vibration modes and associated operation status includes a multi-furcated fiber bundle based optical splitter configured to transmit light to a surface of at least one turbomachinery system shaft through a plurality of optical fiber bundles disposed at a plurality of locations in proximity to the surface of the at least one shaft, in which the plurality of locations together are arranged in a substantially axial direction between the ends of the at least one shaft. The system further includes an array of high-temperature bifurcated fiber bundle based reflectance probes to receive reflectance signals from the shaft surface and send to an array of photosensitive detectors, configured to detect dynamic light reflected from the at least one turbomachinery system shaft surface in response to the transmitted light during rotation of at least one turbomachinery system shaft and generate dynamic reflected light signals there from. A sensing mechanism is configured to determine a torque or vibration on at least one turbomachinery system shaft in response to the dynamic reflected light signal signatures based on time-domain and frequency-domain signal processes.

Turbomachinery system fiberoptic multi-parameter sensing system and method

An EIT system includes a plurality of voltage sources for supplying a corresponding plurality of voltages to a corresponding number of other structures, voltage source calibration means for calibrating each voltage source, and switching means for individually connecting the calibration means to each voltage source in succession during a period when each other structure is in an inactive condition. Calibrating respective voltages and currents for each voltage source compensates for shunt impedance of each voltage source. A method for calibrating the system includes individually connecting the calibration means to each voltage source in succession during a period when each other structure is in an inactive condition for calibrating all of said voltage sources in the same way.

High precision voltage source for electrical impedance tomography

A circuit for applications such as electrical impedance tomography includes a voltage-to-current converter having an input for receiving a voltage waveform and an output for outputting a current waveform to a load at an output resistance for the voltage-to-current converter. The voltage-to-current converter includes resistance control means for adjusting the output resistance of the voltage-to-current converter under computer control. The circuit of the present invention also includes an inductance control circuit operatively connected to the voltage-to-current converter for synthesizing a selected inductance. The inductance control circuit includes inductance control means for adjusting the value of the selected inductance by computer control. The operative connection between the voltage-to-current converter and the inductance control circuit causes application of the selected inductance to the output of the voltage-to-current converter so that an overall output impedance of the current source at the load is both high and controllable.

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Albany, NY, United States of America

Alexander Seth Ross